*{
    font-family: "Helvetica Neue",Helvetica,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","微软雅黑",Arial,sans-serif;
    margin: 0;
    padding: 0;
    /* 动画 */
    animation: d1_m 1.5s;
}
body{
    background-image: linear-gradient(to bottom,#256bac , #6bcbf7);
    height: 100vh;
    background-size: 100%;
    max-height: 100%;
    background-attachment: fixed;
    
}
#main{
    margin-top: 2vw;
    width: 90%;
    margin-left: 2vw;
    
}
#main>div{
    margin-bottom: 3vw;
}
#subject{
    width: 100%;
    margin-left: 2vw;
}
.pick{
    /* margin-right: 20vw; */
    color:rgb(216, 216, 216);
    font-size: 18px;
    margin: 2vw 0 0 2vw;
}
.pick:hover{
    opacity: 0.8;
    cursor: grab;
}
h2{
    color: white;
}
h3{
    color: rgb(228, 228, 228);
}
#bt1{
    margin-top: 5vw;
    margin-left: 5vw;
    text-align: center;
    border: none;
    background-color:rgb(95, 177, 248);
    color: white;
    width: 200px;
    height: 80px;
    font-size: 16px;
    border-radius: 30px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.5);
}
#bt1:hover{
    opacity: 0.8;
}
#overDiv{
    font-size: 20px;
    margin-top: 10vw;
    margin-left: 10vw;
}
@keyframes d1_m {
    from {
        opacity: 0.0;
    }
    to {
        opacity: 1.0;
    }
}